Technical Field
This disclosure relates to an image forming apparatus and a program product used in the image forming apparatus.
Related Art
Electrophotographic image forming apparatuses are known to form an image on both sides of a recording medium.
In such an image forming apparatus, for example, an image is formed together with a detection mark on a first side of a recording sheet. The detection mark on the first side is detected to obtain a change in magnification to image data of the image formed on the first side and a position of the image on the first side. Based on the detected position of the image, an image forming time is corrected, so that an image to be formed on a second side of the recording sheet is aligned with the position of the image formed on the first side. In addition, based on the detected change in magnification, a magnification of image data to be formed on the second side of the recording sheet is corrected, so that a size of the image to be formed on the second side is matched with a size of the image formed on the first side. After these adjustments, image formation is started at the corrected image forming time. At the same time, based on the image data with the corrected magnification, an image is formed on the second side of the recording sheet conveyed again to an image forming position via a sheet reversing passage. Accordingly, the position and size of the image formed on the first side of the recording sheet are matched with the position and size of the image formed on the second side.